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Estimate energy expenditure (METs) from activity counts

Source: R/pa_intensity.R
estimate_ee.Rd

Applies the published ActTrust(R)/GT3X+ regression equation (sqrt(MET) = b0 + b1 * sqrt(activity_counts)) from pa_equations() to convert raw activity counts into estimated metabolic equivalents (METs).

Usage

estimate_ee(
  counts,
  device = c("ACTT", "GT3X+"),
  placement = c("hip", "wrist"),
  equation_set = "batista2026"
)

Arguments

counts

Numeric vector of activity counts (counts/min, over the same epoch length used by the source equation set – 1-minute for "batista2026"). Negative values are treated as 0 with a warning, since the underlying square-root transform is undefined below zero.

device

character(1). "ACTT" (default) or "GT3X+".

placement

character(1). "hip" (default) or "wrist".

equation_set

character(1), passed to pa_equations(). Default "batista2026".

Value

Numeric vector of estimated METs, same length as counts.

See also

pa_equations() for the underlying coefficients and their limitations, classify_pa_intensity() to convert METs into intensity bands.

Examples

estimate_ee(c(0, 5000, 25000, 50000), device = "ACTT", placement = "hip")
#> [1] 1.225449 2.990319 6.242013 9.454025